Goods of relatively small size are typically transported using load carriers which are platforms or boxes preferably mounted on wheels or castors. The platforms may include side walls, in which case they are typically referred to as crates or roll containers, or not include side walls, in which case they are typically referred to as trays, dollies or trolleys. Wheeled load carriers are typically favoured in the logistics of heavy objects. Goods are stored in containers that fit into the receptive platform. Upon transportation or temporary storage, the usually boxlike containers are stacked onto dollies, the wheels of which enable easy handling by hand. The shape and size of the dollies are usually standardized to conform advantageously to industrial container models. While the wheeled load carriers may be moved about by hand, there is also a need to transport a plurality of wheeled load carriers at once. Such a need occurs e.g. when loading or unloading a trailer or a lorry. If a trailer is loaded one wheeled load carrier at a time, the long duration of the operation consumes valuable docking time not to mention inflicted gratuitous vehicle idle time. Also, when transported individually, the wheeled load carriers require thorough and tedious trussing up to prevent unintended movement within the load space. To tackle these disadvantages, adaptor pallets have been developed. These adaptor pallets are usually rather flat and include a deck that has an upper support surface to accommodate a plurality of wheeled load carriers, tracks to guide the wheels thereof and receptive slots to receive the lifting forks of a forklift.
There is also a need to secure the load carriers to the adaptor pallet. Many different securing devices have been developed over time but the locking mechanisms vary depending on the requirements concerning usability, level of security, etc. A prominent type of an adaptor pallet has an open loading end, whereby the wheeled load carriers are secured to the pallet by operating a locking device, preferably a foot-operated locking device. Such adaptor pallets enjoy the benefit of not requiring a separate strap to secure the cargo. One such adaptor pallet has been disclosed in EP 2671814 A, which is particularly advantageous in that the pallet does not require a separate manipulation mechanism for toggling the locking device between an open and closed state. This makes the structure very user-friendly, light and robust. The disclosed locking mechanism makes contact with the chassis of the roll container from below and simply limits the rolling movement of the wheeled load carrier so as to prevent the wheeled load carrier from rolling off the adaptor pallet.
Other interpretation of an adaptor pallet has been disclosed in DE 102009052869 B4 proposing locking tabs that may be toggled between an engaging state and a retracted state. When in the engaging state, the tabs protrude out of the side of the lifting tunnel to grab the wheeled load carrier thus limiting the movement of the wheeled load carrier in several dimensions. When in the retracted state, the tabs are retracted inside the lifting tunnel so as to allow rolling movement of the wheeled load carriers. While very sturdy, the adaptor pallet of DE 102009052869 B4 requires quite a complex manipulation mechanism to operate the locking tabs, which adds weight to the adaptor pallet and makes it susceptible for mechanical failures.
It would therefore be desirable to provide an adaptor pallet, which would capture the usability, lightness and simplicity of the adaptor pallet of EP 2671814 A, but exhibit the securing properties of the adaptor pallet of DE 102009052869 B4. It is therefore an object of at least some of the embodiments herein described to provide a user-friendly and light yet sturdy alternative to transporting may load carriers at once.